One week before the first euros begin their journey from the French central bank to three heavily fortified depots around the capital, a last detachment of Paris policemen will complete a course of training for the launch of the new currency today.

"We have worked to cover every eventuality - while being aware that criminals will use every possible means to get their hands on the first euros", the chief of Paris police, Jean-Paul Proust, said.

He said several thousand officers had been trained over the past six months in guarding the armoured security vans that will transport the money, learning how to spot counterfeit euros, and helping shopkeepers and pensioners get used to the new currency to reduce the risk of fraud and short-changing.

From January 1, when the euro comes into circulation alongside the franc, hundreds officers will be deployed at 2,500 banks, post offices and shops around Paris.

In training sessions on the outskirts of Paris heavily armed officers in police vans have been taught how to respond if the security car they are escorting is ambushed or comes under fire.

Earlier this week a security van carrying francs and euros was attacked by a gang who fired at the vehicle and its occupants. One of the gang was killed as the security guards fired back.

"It's inevitable that there will be attacks," said Jean-Claude Penot, one of the training officers. "The vans represent too tempting a target. We have to be ready for that, and the only way to do it is to practise the right techniques, in a number of different situations."